1. Field of the Invention
The present invention relates to a separate type air conditioner which has an evaporator as an indoor heat exchanger and a condenser as an outdoor heat exchanger.
2. Description of the Prior Art
Generally, an air conditioner is an appliance for maintaining optimum temperature conditions in a room. Particularly, temperature is adjusted to a proper degree by exhausting heat out of the room by means of a refrigerant cycle.
As shown in FIG. 1, a refrigerant cycle comprises a compressor 2 for compressing refrigerant into a high temperature and high pressure, a condenser 3 serving as an outside heat exchanger for liquefying the high temperature and high pressure refrigerant into a normal temperature and high pressure, a capillary tube 4 for depressurizing refrigerant, and an evaporator 1 for lowering the temperature in the room by exchanging heat of the air in the room with the refrigerant received from the capillary tube 4. Additionally, blowing fans 5 and 6 for enhancing the efficiency of the heat exchange are installed on the condenser 3, and the compressor 1, respectively.
Particulary, the evaporator 1 consists of a plurality of fins A arranged close to each other and a plurality of U-shaped heat-exchanging pipes B passing through the fins A.
These heat-exchanging pipes B constitute a refrigerant circulating passage. The heat exchanging pipes B are interconnected by connecting pipes C which connect the ends of respective heat-exchanging pipes B with each other.
The manner of aligning these heat-exchanging pipes B seriously affects the quality of the evaporator 1. Therefore, there have been many experiments and studies about how to make a good arrangement of heat-exchanging pipes B so as to improve quality of the evaporator 1.
A prior art arrangement of the heat-exchanging pipes B of the evaporator 1 is shown in FIG. 2 in greater detail. What is shown in FIG. 2 is the pipe arrangement of the evaporator 1 of a separate air conditioner having the evaporator 1 and the condenser 3, each of which being installed as a separate unit.
As shown, the evaporator 1 is divided into a front section 10 and a rear section 20. The heat-exchanging pipes B installed on the front section 10 and the rear section 20 are respectively aligned in two lines, i.e., a front line (11-1, 11-2, . . . , 11-10 in the front section 10, and a front line 21-1, 21-2 . . . , 22-5 of the rear section 20) and a rear line (12-1, 12-2, . . . , 12-10 of the front section 10, and a rear line 22-1, 22-2, . . . , 22-5 of the rear section 20). Shown in solid lines are connecting pipes C for connecting the ends of respective heat-exchanging pipes B with each other, and shown in dotted lines are connecting portions of respective heat-exchanging pipes B. The connecting portions are positioned at a side of the fins A opposite to the connecting pipes C.
Thus, the refrigerant which has passed through the capillary tube 4 is introduced into a 4-gate distributor 7' and divided into four passages, that is a first passage, a second passage, a third passage, and a fourth passage. In the first passage, refrigerant enters into 22-2, passes through 22-3, 22-4, 22-5, 21-5, 21-4, 21-3, and exits from 21-2. In the second passage, refrigerant enters into 22-1, and passes through 21-1, 11-1, 11-2, 11-3, 12-3, 12-2, then exits from 12-1. Refrigerant enters into 11-8 and passes through 11-7, 11-6, 11-5, 11-4, 12-4, and 12-5, then exits from 12-6 in the third passage. Lastly, in the fourth passage, refrigerant enters into 11-9, passes through 11-10, 12-10, 12-9, 12-8, and exits from 12-7. While the refrigerant flows through the four passages, it is evaporated to cool the air around the evaporator 1, and then it is converged in a 4-gate connecter 8' to flow to the compressor (not shown).
The above described arrangement of the heat-exchanging pipes B of the evaporator 1 makes the evaporation process successful without a pressure loss of refrigerant passing through the heat-exchanging pipes B.
According to the conventional manner in which the heat-exchanging pipes B of the evaporator 1 are arranged, however, there are great differences in the temperature of refrigerant from one refrigerant passages to the other. Moreover, temperature differences also occur between the parts of each passage, i.e, inlet part, middle part, and outlet part thereof. Specifically, it has turned out that the temperature ranges from 4.9.degree. C. to 16.8.degree. C., of which a maximum difference is 11.9.degree. C.
As the temperature difference of refrigerant is great between the passages and the parts of a passage, there is a serious drawback in the performance of the evaporator 1. Also, some of the refrigerant passing through the evaporator 1 does not evaporate and remains in a liquid state, or turns to a frozen state.